The study of the collective properties of the nucleus is a powerful tool to understand the structure which lays inside the nucleus. A successful technique which has been used in this field is the measurement of the gamma decay of the highly collective state Giant Dipole Resonance (GDR). In fact, GDR can be used as a probe for the internal structure of hot nuclei and, in addition, constitutes a clock for the thermalization process.
Using the fusion-evaporation reaction, it has been recently possible to study i) the yield of the high energy gamma ray emission of the dynamic dipole which takes place during the fusion process and ii) the degree of isospin mixing at high temperature in the decay of 80Zr. In the first case it is important to stress the fact that the prediction of the theoretical models differs depending on the type of nuclear equation of state (EOS) used in the calculations while in the second physics case the data are relative to the heaviest nucleus N=Z which has been possible to populate in the channel I=0 using fusion-evaporation reaction.
In both experiments, the data have been acquired at the Laboratori Nazionali di Legnaro using the HECTOR-GARFIELD array. The high energy gamma-rays have been measured in 8 large volume BaF2 detectors in coincidence with light charged particle (measured in ~ 100 E-e telescopes) and reaction residues (measured with an array of phoswich detectors).